Failed Vocalis Muscle Monitoring During Thyroid Surgery Resulting From Residual Muscle Relaxation.

Postoperative paralysis of the vocal cords resulting from intraoperative surgical injury of the recurrent laryngeal nerve is one of the most serious complications of elective thyroid surgery. The chance of injury is reduced by using intraoperative neuromonitoring (IONM). This educational report describes a case of IONM failure resulting from residual muscle relaxation that was restored by administration of sugammadex. It discusses possible pharmacology explanations and provides recommendations for how to prevent this situation in daily practice.

Intraoperative mandibular nerve block with peripheral nerve stimulator for temporomandibular joint ankylosis.

We describe the use of peripheral nerve stimulator for mandibular nerve block intraoperatively in a 4.5year old child with complete temporomandibular joint ankyloses. The block was not possible preoperatively, therefore, it was administered after release of ankyloses. The use of peripheral nerve stimulator increased the chances of a successful block. No intraoperative analgesics and muscle relaxants were required. Postoperative pain relief was excellent. Peripheral nerve stimulator is an easy way of for accurate needle tip placement for mandibular nerve block in patients with distorted anatomy.

Low-Dose or High-Dose Rocuronium Reversed with Neostigmine or Sugammadex for Cesarean Delivery Anesthesia: A Randomized Controlled Noninferiority Trial of Time to Tracheal Intubation and Extubation.

BACKGROUND: Rocuronium for cesarean delivery under general anesthesia is an alternative to succinylcholine for rapid-sequence induction of anesthesia because of the availability of sugammadex for reversal of neuromuscular blockade. However, there are no large well-controlled studies in women undergoing general anesthesia for cesarean delivery. The aim of this noninferiority trial was to determine whether rocuronium and sugammadex confer benefit in time to tracheal intubation (primary outcome) and other neuromuscular blockade outcomes compared with succinylcholine, rocuronium, and neostigmine in women undergoing general anesthesia for cesarean delivery. METHODS: We aimed to enroll all women undergoing general anesthesia for cesarean delivery in the 2 participating university hospitals (Brno, Olomouc, Czech Republic) in this single-blinded, randomized, controlled study. Women were randomly assigned to the ROC group (muscle relaxation induced with rocuronium 1 mg/kg and reversed with sugammadex 2-4 mg/kg) or the SUX group (succinylcholine 1 mg/kg for induction, rocuronium 0.3 mg/kg for maintenance, and neostigmine 0.03 mg/kg for reversal of the neuromuscular blockade). The interval from the end of propofol administration to tracheal intubation was the primary end point with a noninferiority margin of 20 seconds. We recorded intubating conditions (modified Viby-Mogensen score), neonatal outcome (Apgar score <7; umbilical artery pH), anesthesia complications, and subjective patient complaints 24 hours after surgery. RESULTS: We enrolled 240 parturients. The mean time to tracheal intubation was 2.9 seconds longer in the ROC group (95% confidence interval, -5.3 to 11.2 seconds), noninferior compared with the SUX group. Absence of laryngoscopy resistance was greater in the ROC than in the SUX groups (ROC, 87.5%; SUX, 74.2%; P = 0.019), but there were no differences in vocal cord position (P = 0.45) or intubation response (P = 0.31) between groups. No statistically significant differences in incidence of anesthesia complications or in neonatal outcome were found (10-minute Apgar score <7, P = 0.07; umbilical artery pH, P = 0.43). The incidence of postpartum myalgia was greater in the SUX group (ROC 0%; SUX 6.7%; P = 0.007). The incidence of subjective complaints was lower in the ROC group (ROC, 21.4%; SUX, 37.5%; P = 0.007). CONCLUSIONS: We conclude that rocuronium for rapid-sequence induction is noninferior for time to tracheal intubation and is accompanied by more frequent absence of laryngoscopy resistance and lower incidence of myalgia in comparison with succinylcholine for cesarean delivery under general anesthesia.

The effect of magnesium sulphate on intubating condition for rapid-sequence intubation: a randomized controlled trial.

STUDY OBJECTIVES: We compared magnesium sulphate with control, ketamine, rocuronium prime, and large-dose rocuronium (0.9 mg/kg) with regard to intubation conditions during rapid-sequence induction. DESIGN: This is a prospective, randomized, double-blinded study. SETTING: The setting is at an operating room in a university-affiliated hospital. PATIENTS: One hundred ten patients scheduled for general anesthesia were randomly allocated to the following 5 groups in equal numbers. INTERVENTIONS: The control and rocuronium 0.9 groups received rocuronium 0.6 and 0.9 mg/kg, respectively; the ketamine group was given 0.5 mg/kg ketamine 2 minutes before 0.6 mg/kg rocuronium; the rocuronium prime group received 0.06 mg/kg rocuronium 3 minutes before 0.54 mg/kg rocuronium; and the magnesium group received 50 mg/kg magnesium sulphate. Intubation was initiated 50 seconds after the rocuronium injection. MEASUREMENTS: Intubating condition (primary outcome), rocuronium onset, rocuronium duration, train-of-four ratio upon intubation, and hemodynamic variables (secondary outcomes) were recorded. MAIN RESULTS: The excellent intubating condition was more frequent in the magnesium group (P < .05). Onset of neuromuscular block was shorter in the magnesium group than in the control, ketamine, and rocuronium prime groups (P < .05). No difference in onset time was found between the magnesium and rocuronium 0.9 groups. Block duration was longest in the rocuronium 0.9 group. The train-of-four ratio on intubation was lowest in the rocuronium prime group. The only adverse event was a burning or heat sensation reported by 5 patients in the magnesium group. CONCLUSIONS: Magnesium sulphate pretreatment was most likely to provide excellent intubating condition for rapid-sequence intubation compared with the control, ketamine pretreatment, rocuronium prime, and large-dose rocuronium. However, magnesium sulphate administration is associated with a burning or heat sensation.

A technical description of a novel pharmacological anesthesia robot.

To control the three components of general anesthesia (hypnosis, analgesia, and neuromuscular blockade), an automated closed-loop, anesthesia-drug delivery system (McSleepy) was developed. Bispectral index was used as the control variable for hypnosis, the analgoscore for analgesia, and phonomyography for neuromuscular blockade. McSleepy can be used to control the induction, maintenance and emergence from general anesthesia. To do so, a large touch screen is used to provide a user friendly interface, permitting bidirectional communication: the user giving information about the different stages of anesthesia, and the system prompting the anesthesiologist to perform certain actions such as mask ventilation, intubation or waking-up the patient using audio clips with voice commands. Several safety features were implemented to provide a secure and reliable anesthesia. Preliminary results of 15 patients are presented in this paper. Evaluation of McSleepy was done through an assessment of its clinical performance and using Varvel's performance indices. The system was found to be clinically useful by providing good precision in drug administration and reliable results for the duration of a general anesthesia.

Effects of valproic acid and magnesium sulphate on rocuronium requirement in patients undergoing craniotomy for cerebrovascular surgery.

BACKGROUND: Many anti-epileptics cause resistance to non-depolarizing neuromuscular blocking agents, but this has not been reported for valproic acid (VPA). We hypothesized that VPA would increase the rocuronium requirement and that magnesium sulphate (MgSO(4)) may reduce this increase. METHODS: Fifty-five patients undergoing cerebrovascular surgeries were studied. Subjects were allocated into three groups at a 1:1:1 ratio: Groups VM, VC, and C. Groups VM and VC were given VPA premedication; Group C was not. A rocuronium injection (0.6 mg kg(-1) i.v.) was administered to Group VM, followed by MgSO(4) as a 50 mg kg(-1) i.v. bolus and 15 mg kg(-1) h(-1) infusion. The same volume of 0.9% saline was administered to the other groups. Supplementary rocuronium (0.15 mg kg(-1)) was given whenever the train-of-four count reached 2. Rocuronium requirements (primary outcome), mean arterial pressure (MAP), heart rate (HR), nausea, vomiting, shivering, and use of anti-emetics and nicardipine were compared. RESULTS: Group VC showed the highest rocuronium requirement [mg kg(-1) h(-1): 0.47 (0.08) vs 0.33 (0.12) (Group C), 0.31 (0.07) (Group VM); P<0.001]. MAP, intraoperative HR, nausea, vomiting, shivering, and use of anti-emetics and nicardipine were not significantly different among the groups. Postoperative HR was lower in Group VM than in Group VC. CONCLUSIONS: VPA increased the rocuronium requirement, and MgSO(4) infusion attenuated this increase.

Testing rocuronium-induced neuromuscular blockade at the stapedius muscle using stapedius reflex measurements.

BACKGROUND: Neuromuscular monitoring prior to emergence from anaesthesia has been shown to be necessary to achieve adequate airway protection in order to decrease postoperative pulmonary complications. In the present study we hypothesized that stapedius reflex measurement allows the detection of residual neuromuscular blockade using the stapedius muscle following the administration of rocuronium. PATIENTS AND METHODS: Parallel stapedius and acceleromyographic measurements were performed on 20 patients undergoing cholecystectomy. Acceleromyographic measurements were continuously performed during the course of anaesthesia, whereas the stapedius reflex was measured on different occasions: (1) after premedication but before anaesthesia induction, (2) after induction, but before administration of muscle relaxant, (3) after administration of muscle relaxant, (4) during the course of surgical anaesthesia at regular intervals, and (5) continuously performed during emergence from anaesthesia, until the stapedius reflex threshold returned to normal. RESULTS: The intensity of the sound energy at which the stapedius reflex is detectable was similar: 89.5 ± 9.9 dB(mean ± SD) after premedication and after anaesthetic induction. However, after administration of rocuronium, when the twitch height decreased to 5%, the stapedius reflex disappeared, indicating a total block of the stapedius muscle.During the recovery phase (twitch>10%) significantly higher sound energies compared to baseline values were necessary to evoke the reflex, indicating residual inhibition of the stapedius muscle. At the point where stapedius reflex threshold returned to normal the twitch height averaged about 50% showing low sensitivity of the tympanometry in detecting residual neuromuscular blockade. CONCLUSIONS: The neuromuscular effect of rocuronium on the stapedius muscle can be detected using stapedius reflex measurements. Due to its methodological limitation and low sensitivity, the method cannot be recommended for the monitoring of residual neuromuscular blockade.

Comparison of recovery times from rocuronium-induced muscle relaxation after reversal with three different doses of sugammadex and succinylcholine during electroconvulsive therapy.

PURPOSE: This study was conducted to compare recovery times from rocuronium-induced muscle relaxation after reversal with three different doses of sugammadex with succinylcholine during electroconvulsive therapy (ECT). METHODS: Seventeen patients who were scheduled to undergo ECT were studied. Anesthesia was induced by use of propofol (1.0 mg/kg) followed by either succinylcholine (SCC) (1 mg/kg) or rocuronium (0.6 mg/kg). Assisted mask ventilation was initiated with 100% oxygen. After T1 was assessed as being zero by neuromuscular monitoring, an electroshock stimulus was applied bilaterally. Patients receiving rocuronium were infused with 16, 8, or 4 mg/kg sugammadex immediately after the seizure stopped to reverse the muscle relaxation. Neuromuscular monitoring was continued until recovery of the train-of-four ratio to 0.9 at the tibial nerve in the leg. The times to recovery of T1 to 10 and 90% with both relaxants were compared. RESULTS: The time to recovery of T1 to 90% after 16 mg/kg sugammadex was shorter than that in subjects treated with SCC (p = 0.046), whereas that after 4 mg/kg sugammadex was longer than that in subjects treated with SCC (SCC group: 429 ± 65 s, 16 mg/kg sugammadex group: 387 ± 63 s*, 8 mg/kg sugammadex group: 462 ± 66 s, 4 mg/kg sugammadex group: 563 ± 45 s(*,#); *p < 0.05 compared with SCC, (#)p < 0.01 compared with 16 mg/kg sugammadex). CONCLUSIONS: This study demonstrates the efficacy of rocuronium-sugammadex as an alternative to SCC for muscle relaxation during ECT, and indicates that 8 mg/kg sugammadex produces equally rapid recovery from rocuronium muscular relaxation compared with spontaneous recovery from 1 mg/kg SCC during ECT.

[Case-Report: Reversal of a deep neuromuscular block with sugammadex after rapid sequence induction with high-dose rocuronium bromide]. / Kasuistik: Rapid Sequence Induction - Reversion einer tiefen neuromuskulären Blockade durch Sugammadex.

Sugammadex can reverse rocuronium-induced muscular relaxation by encapsulation of steroidal muscle relaxants without muscarinergic side effects. Clinical studies show effective dose-dependent reversal of neuromuscular blockades after rocuronium and vecuronium. We report on a patient with deep neuromuscular block at the end of surgery following rapid sequence induction of anesthesia with high-dose rocuronium, who could rapidly be reversed without side effects after adequate i.v. sugammadex application.

Infusion requirements and reversibility of rocuronium at the corrugator supercilii and adductor pollicis muscles.

BACKGROUND: The aim of this study is to compare the infusion rates required to maintain a constant neuromuscular block and the reversibility of rocuronium at the corrugator supercilii muscle (CSM) and the adductor pollicis muscle (APM). METHODS: We randomly allocated 30 female patients into two groups of 15 patients each to monitor neuromuscular block at either the CSM or the APM. After induction of anaesthesia and laryngeal mask insertion, contraction of the CSM to the facial nerve stimulation or that of the APM to the ulnar nerve stimulation was quantified using an acceleromyograph during 1.0-1.5% end-tidal sevoflurane anaesthesia. All the patients received a bolus of 1 mg/kg rocuronium. When the first twitch (T1) of train-of-four (TOF) recovered to 10% of the control, rocuronium infusion was commenced and maintained at T1 of 10% of the control at the CSM or APM for 120 min. Immediately after rocuronium infusion was discontinued, the time required for 0.04 mg/kg neostigmine-facilitated recovery to a TOF ratio of 0.9 was recorded. RESULTS: Rocuronium infusion dose after a lapse of 120 min was significantly larger in the CSM than in the APM [7.1 (2.3) vs. 4.7 (2.6) microg/kg/min; P=0.001]. The time for facilitated recovery was shorter in the CSM than in the APM [11.4 (3.8) vs. 16.2 (6.0) min; P=0.016]. CONCLUSION: A larger rocuronium infusion dose was required to maintain a constant neuromuscular block at the CSM. Neostigmine-mediated reversal was faster at the CSM.

Corrección de la curva dosis-respuesta acumulativa de atracurio y rocuronio / Correction of the cumulative dose-response to atracurium and rocurionium

Introducción: La curva dosis-respuesta acumulativa es un método práctico para evaluar las dosis efectivas de atracurio y rocuronio. Debido a sus características farmacocinéticas, los resultados de dicha curva subestiman la potencia de ambos fármacos en comparación con los que resultan de la administración de dosis únicas. El objetivo de la presente investigación es corregir aquella técnica y hacer las dos estadísticamente equivalentes. Material y métodos: En dos grupos de pacientes electivos se utilizó atracurio o rocuronio para calcular sus potencias por el método de las dosis únicas (n = 45 c/u) o acumulativas (n = 11 c/u). El efecto de cada dosis se determinó por electromiografía, y después de sus transformaciones logaritmo-probits, considerando gamma como la relación probit/log, se obtuvieron las DE 50 y 90 resolviendo la ecuación de Hill para cada sujeto. La técnica acumulativa se corrigió al utilizar las cifras actuales para las dosis y sus efectos, en lugar de los valores acumulativos a partir de la segunda administración. Resultados: Las DE 50 de las técnicas de dosis única, acumulativa y corregida fueron: 172 ± 73, 264 ± 52 y 162 ± 81 mcg/kg respectivamente, cuando se utilizó rocuronio, y 141 ± 61, 193 ± 53 y 141 ± 70 respectivamente, cuando se utilizó atracurio. En el caso de las DE 90' los valores fueron 233 ± 98, 327 ± 65, 254 ± 126 y 222 ± 96, 279 ± 77 y 254 ± 126, en el mismo orden. No se detectaron diferencias significativas entre los métodos de dosis única y corregida, mientras que los valores de las dosis acumulativas fueron significativamente mayores. Discusión y conclusiones: En las condiciones de la presente investigación, una sencilla corrección del método acumulativo reproduce razonable y estadísticamente la potencia del atracurio y del rocuronio evaluada por las dosis únicas.

Introduction: The cumulative dose-response curve is a practical method to evaluate the effective doses of atracurium and rocuronium. When compared with those obtained by single administrations, the resulting figures underestimate their potency due to pharmacokinetic features. The purpose of this trial is to correct the cumulative technique and to make both statistically equivalent. Material & Methods: Single (n = 45 e/a) or cumulative (n = 11 e/a) doses of atracurium or rocuronium were administered to elective patients and maximal effect assessed by electromyography. A regression line was obtained after log dose-probit effect transformation, and considering gamma as the probit/log ratio, ED 50 and 90 were calculated resolving the Hill equation for each patient. The cumulative technique was corrected by using actual figures instead of cumulative ones, starting at second administration. Results: ED 50 were 172 ± 73, 264 ± 52 y 162 ± 81 mcg/kg as single, cumulative dose or corrected respectively for rocuronium and 141 ± 61, 193 ± 53 y 141 ± 70 for atracurium. ED 90 was 233 ± 98,327 ± 65, 254 ± 126, 222 ± 96, 279 ± 77 y 254 ± 126 in the same order. Non-significant differences between single dose and corrected method were noticed. Cumulative values were significantly larger. Conclusion: In keeping with the conditions of the present trial, a simple correction made to the cumulative method reasonably and statistically reproduces atracurium and rocuronium potencies evaluated by single dose-responses technique.

Introdução: A curva dose-resposta acumulativa é um método prático de avaliação das doses efetivas de atracúrio e rocuronio. Dada suas características farmacocinéticas, os resultados dessa curva subestimam a potência de ambos fármacos em comparação com os resultados decorrentes da administração de dose únicas. O objetivo da presente pesquisa é corrigir aquela técnica e tornar as duas estatisticamente equivalentes. Material e métodos: Dois grupos de pacientes eletivos receberam atracúrio ou rocurônio com o objetivo de calcular as potências destes fármacos pelo método das doses únicas (n = 45 c/u) ou acumulativas (n = 11 c/u). Foi determinado o efeito de cada dose por eletromiografia, e por transformação log-probits (considerando gama a relação probit/log), obtiveram-se as DE 50 e 90 resolvendo a equação de Hill para cada sujeito. A técnica acumulativa foi corrigida utilizando as cifras atuais para doses e seus efeitos, em lugar dos valores acumulativos, a partir da segunda administração. Resultados: As DE 50 das técnicas de dose única, acumulativa e corrigida foram: 172 ± 73, 264 ± 52 e 162 ± 81 mcg/kg, respectivamente, quando se utilizou rocurônio, e 141 ± 61, 193 ± 53 e 141 ± 70, respectivamente, quando se utilizou atracúrio. No caso das DE 90' os valores foram 233 ± 98, 327 ± 65, 254 ± 126 e 222 ± 96, 279 ± 77 e 254 ± 126, na mesmo ordem. Não foram observadas diferenças significativas entre os métodos (de dose única e corrigida), ao passo que os valores das doses acumulativas foram significativamente maiores. Discussão e conclusões: Nas condições da presente pesquisa, uma simples correção do método acumulativo reproduz de forma razoável e estatisticamente as potências do atracúrio e rocuronio avaliadas por doses únicas.

Corrección de la curva dosis-respuesta acumulativa de atracurio y rocuronio / Correction of the cumulative dose-response to atracurium and rocurionium

Introducción: La curva dosis-respuesta acumulativa es un método práctico para evaluar las dosis efectivas de atracurio y rocuronio. Debido a sus características farmacocinéticas, los resultados de dicha curva subestiman la potencia de ambos fármacos en comparación con los que resultan de la administración de dosis únicas. El objetivo de la presente investigación es corregir aquella técnica y hacer las dos estadísticamente equivalentes. Material y métodos: En dos grupos de pacientes electivos se utilizó atracurio o rocuronio para calcular sus potencias por el método de las dosis únicas (n = 45 c/u) o acumulativas (n = 11 c/u). El efecto de cada dosis se determinó por electromiografía, y después de sus transformaciones logaritmo-probits, considerando gamma como la relación probit/log, se obtuvieron las DE 50 y 90 resolviendo la ecuación de Hill para cada sujeto. La técnica acumulativa se corrigió al utilizar las cifras actuales para las dosis y sus efectos, en lugar de los valores acumulativos a partir de la segunda administración. Resultados: Las DE 50 de las técnicas de dosis única, acumulativa y corregida fueron: 172 ± 73, 264 ± 52 y 162 ± 81 mcg/kg respectivamente, cuando se utilizó rocuronio, y 141 ± 61, 193 ± 53 y 141 ± 70 respectivamente, cuando se utilizó atracurio. En el caso de las DE 90 los valores fueron 233 ± 98, 327 ± 65, 254 ± 126 y 222 ± 96, 279 ± 77 y 254 ± 126, en el mismo orden. No se detectaron diferencias significativas entre los métodos de dosis única y corregida, mientras que los valores de las dosis acumulativas fueron significativamente mayores. Discusión y conclusiones: En las condiciones de la presente investigación, una sencilla corrección del método acumulativo reproduce razonable y estadísticamente la potencia del atracurio y del rocuronio evaluada por las dosis únicas.(AU)

Introduction: The cumulative dose-response curve is a practical method to evaluate the effective doses of atracurium and rocuronium. When compared with those obtained by single administrations, the resulting figures underestimate their potency due to pharmacokinetic features. The purpose of this trial is to correct the cumulative technique and to make both statistically equivalent. Material & Methods: Single (n = 45 e/a) or cumulative (n = 11 e/a) doses of atracurium or rocuronium were administered to elective patients and maximal effect assessed by electromyography. A regression line was obtained after log dose-probit effect transformation, and considering gamma as the probit/log ratio, ED 50 and 90 were calculated resolving the Hill equation for each patient. The cumulative technique was corrected by using actual figures instead of cumulative ones, starting at second administration. Results: ED 50 were 172 ± 73, 264 ± 52 y 162 ± 81 mcg/kg as single, cumulative dose or corrected respectively for rocuronium and 141 ± 61, 193 ± 53 y 141 ± 70 for atracurium. ED 90 was 233 ± 98,327 ± 65, 254 ± 126, 222 ± 96, 279 ± 77 y 254 ± 126 in the same order. Non-significant differences between single dose and corrected method were noticed. Cumulative values were significantly larger. Conclusion: In keeping with the conditions of the present trial, a simple correction made to the cumulative method reasonably and statistically reproduces atracurium and rocuronium potencies evaluated by single dose-responses technique.(AU)

IntroduþÒo: A curva dose-resposta acumulativa é um método prático de avaliaþÒo das doses efetivas de atracúrio e rocuronio. Dada suas características farmacocinéticas, os resultados dessa curva subestimam a potÛncia de ambos fármacos em comparaþÒo com os resultados decorrentes da administraþÒo de dose únicas. O objetivo da presente pesquisa é corrigir aquela técnica e tornar as duas estatisticamente equivalentes. Material e métodos: Dois grupos de pacientes eletivos receberam atracúrio ou rocur¶nio com o objetivo de calcular as potÛncias destes fármacos pelo método das doses únicas (n = 45 c/u) ou acumulativas (n = 11 c/u). Foi determinado o efeito de cada dose por eletromiografia, e por transformaþÒo log-probits (considerando gama a relaþÒo probit/log), obtiveram-se as DE 50 e 90 resolvendo a equaþÒo de Hill para cada sujeito. A técnica acumulativa foi corrigida utilizando as cifras atuais para doses e seus efeitos, em lugar dos valores acumulativos, a partir da segunda administraþÒo. Resultados: As DE 50 das técnicas de dose única, acumulativa e corrigida foram: 172 ± 73, 264 ± 52 e 162 ± 81 mcg/kg, respectivamente, quando se utilizou rocur¶nio, e 141 ± 61, 193 ± 53 e 141 ± 70, respectivamente, quando se utilizou atracúrio. No caso das DE 90 os valores foram 233 ± 98, 327 ± 65, 254 ± 126 e 222 ± 96, 279 ± 77 e 254 ± 126, na mesmo ordem. NÒo foram observadas diferenþas significativas entre os métodos (de dose única e corrigida), ao passo que os valores das doses acumulativas foram significativamente maiores. DiscussÒo e conclus§es: Nas condiþ§es da presente pesquisa, uma simples correþÒo do método acumulativo reproduz de forma razoável e estatisticamente as potÛncias do atracúrio e rocuronio avaliadas por doses únicas.(AU)

Reversal of profound neuromuscular block by sugammadex administered three minutes after rocuronium: a comparison with spontaneous recovery from succinylcholine.

BACKGROUND: Rocuronium in intubation doses provides similar intubation conditions as succinylcholine, but has a longer duration of action. This study compared time to sugammadex reversal of profound rocuronium-induced neuromuscular block with time to spontaneous recovery from succinylcholine. METHODS: One hundred and fifteen adult American Society of Anesthesiologists Class I-II surgical patients were randomized to this multicenter, safety-assessor-blinded, parallel group, active-controlled, Phase IIIa trial. Anesthesia was induced and maintained with propofol and an opioid. Neuromuscular transmission was blocked and tracheal intubation facilitated with 1.2 mg/kg rocuronium or 1 mg/kg succinylcholine. Sugammadex (16 mg/kg) was administered 3 min after rocuronium administration. Neuromuscular function was monitored by acceleromyography. The primary efficacy endpoint was the time from the start of relaxant administration to recovery of the first train-of-four twitch (T(1)) to 10%. RESULTS: One hundred and ten patients received study treatment. Mean times to recovery of (T(1)) to 10% and (T(1)) to 90% were significantly faster in the rocuronium-sugammadex group (4.4 and 6.2 min, respectively), as compared with the succinylcholine group (7.1 and 10.9 min, respectively; all P < 0.001). Timed from sugammadex administration, the mean time to recovery of (T(1)) to 10%, (T(1)) to 90%, and the train-of-four (T(4)/T(1)) ratio to 0.9 was 1.2, 2.9, and 2.2 min, respectively. Reoccurrence of the block was not observed. There were no serious adverse events related to study treatments. CONCLUSION: Reversal of profound high-dose rocuronium-induced neuromuscular block (1.2 mg/kg) with 16 mg/kg sugammadex was significantly faster than spontaneous recovery from 1 mg/kg succinylcholine.

Improved neuromuscular blockade using a novel neuromuscular blockade advisory system: a randomized, controlled, clinical trial.

BACKGROUND: Conventional incremental bolus administration of neuromuscular blocking (NMB) drugs is associated with limitations in intraoperative control, potential delays in recovery, and residual blockade in the postanesthetic period. To overcome such limitations, we developed a novel adaptive control computer program, the Neuromuscular Blockade Advisory System (NMBAS). The NMBAS advises the anesthesiologist on the timing and dose of NMB drugs based on a sixth-order Laguerre model and the history of the patient's electromyographic responses. Here, we tested the hypothesis that the use of the NMBAS improves NMB compared to standard care. METHODS: We conducted a prospective, randomized, controlled, blinded, parallel-group, clinical trial with n = 73 patients (ASA physical status I-III) undergoing abdominal surgery under general anesthesia > or =1.5 h with NMB using rocuronium. Patients were allocated to standard care or NMBAS-guided rocuronium administration. The primary outcome variable was the incidence of intraoperative events reflecting inadequate NMB. Secondary outcome variables included train-of-four (TOF) ratios at the end of surgery before reversal, the total doses of rocuronium, reversal agents, anesthetics and other drugs, the incidence of postoperative adverse events, and the incidence of anesthesiologist noncompliance with NMBAS recommendations. RESULTS: Of 73 enrolled patients, n = 30 per group were eligible for analysis. Patient demographics were comparable between the groups. The incidence in total intraoperative events associated with inadequate NMB was significantly lower in the NMBAS group compared to standard care (8/30 vs 19/30; P = 0.004). Mean TOF ratios at the end of surgery before reversal were higher in the NMBAS group (0.59 [95% CI, 0.48-0.69] vs 0.14 [95% CI, 0.04-0.24]; P < 0.0001). Total administered doses of rocuronium, reversal drugs, and other drugs, and the incidence of postoperative adverse events were not different. CONCLUSIONS: Compared to standard practice, NMBAS-guided care was associated with improved NMB quality and higher TOF ratios at the end of surgery, potentially reducing the risk of residual NMB and improving perioperative patient safety.

Comparison between use of neuromuscular blocking agent and placebo with the intubating laryngeal mask airway.

INTRODUCTION: The intubating laryngeal mask airway (ILMA) is a specially-designed airway device that can be used for endotracheal intubation without direct laryngoscopy. The advantage of this device is that it allows blind endotracheal intubation with a predictably high success rate. The use of neuromuscular blocking agents in facilitating the use of the ILMA has been investigated in the Western population with a quoted successful intubation rate of 88-96 percent. This randomised, double-blind study aimed to see if the use of neuromuscular blocking agent is necessary for successful intubations. METHODS: A total of 150 patients, rated categories 1 and 2 on the American Society of Anesthesiology Physical Status Classification System, were induced with propofol 2.5 mg/kg and fentanyl 2 microg/kg. After insertion of the ILMA, the patients received either saline or 0.6 mg/kg of rocuronium. After 90 seconds, tracheal intubation was attempted using the specially-designed silicon endotracheal tube. In addition to the success rate of intubation, the incidence of complications was also recorded. RESULTS: The success rate for tracheal intubation within three attempts was 93.3 percent for the saline group and 92.0 percent for the rocuronium group; this was statistically insignificant. The time to securing the airway was 11.5 seconds for the saline group, compared to 10.0 seconds in the rocuronium group, but this was statistically insignificant. The incidence of coughing during insertion of the endotracheal tube was 42.7 percent in the saline group as compared to 1.3 percent in the rocuronium group (p-value is less than 0.001). 12 percent of the patients in the saline group moved during intubation, while none was reported to move in the rocuronium group (p-value is 0.003). These results compared favourably with rates quoted in studies conducted on Western populations. CONCLUSION: The intubating laryngeal mask airway-assisted intubation yields a high success rate, which was similar between the paralysed and non-paralysed patients, with no statistical significance. However, the non-paralysed patients were prone to coughing and movements during intubation, requiring supplemental propofol.

Reversal of rocuronium-induced (1.2 mg/kg) profound neuromuscular block by sugammadex: a multicenter, dose-finding and safety study.

BACKGROUND: Reversal of rocuronium-induced neuromuscular blockade can be accomplished by chemical encapsulation of rocuronium by sugammadex, a modified gamma-cyclodextrin derivative. This study investigated the efficacy and safety of sugammadex in reversing rocuronium-induced profound neuromuscular blockade at 5 min in American Society of Anesthesiologists physical status I and II patients. METHODS: Forty-five American Society of Anesthesiologists physical status I and II patients (aged 18-64 yr) scheduled to undergo surgical procedures (anticipated anesthesia duration >/= 90 min) were randomly assigned to a phase II, multicenter, assessor-blinded, placebo-controlled, parallel, dose-finding study. Anesthesia was induced and maintained with propofol and an opioid. Profound neuromuscular blockade was induced with 1.2 mg/kg rocuronium bromide. Sugammadex (2.0, 4.0, 8.0, 12.0, or 16.0 mg/kg) or placebo (0.9% saline) was then administered 5 min after the administration of rocuronium. Neuromuscular function was monitored by acceleromyography, using train-of-four nerve stimulation. Recovery time was the time from the start of administration of sugammadex or placebo, to recovery of the train-of-four ratio to 0.9. Safety assessments were performed on the day of the operation and during the postoperative and follow-up period. RESULTS: A total of 43 patients received either sugammadex or placebo. Increasing doses of sugammadex reduced the mean recovery time from 122 min (spontaneous recovery) to less than 2 min in a dose-dependent manner. Signs of recurrence of blockade were not observed. No serious adverse events related to sugammadex were reported. Two adverse events possibly related to sugammadex were reported in two patients (diarrhea and light anesthesia); however, both patients recovered without sequelae. CONCLUSIONS: Sugammadex rapidly and effectively reversed profound rocuronium-induced neuromuscular blockade in humans and was well tolerated.

Skin reactions to intradermal neuromuscular blocking agent injections: a randomized multicenter trial in healthy volunteers.

BACKGROUND: Numerous reports confirm the performance of intradermal tests for the diagnosis of anaphylaxis during anesthesia; however, there is controversy over their diagnostic value regarding the newer neuromuscular blocking agents (NMBAs). METHODS: One hundred eleven healthy volunteers were randomly assigned to receive intradermal injections of two NMBAs, at five increasing concentrations. A concentration was considered as a reactive concentration when it led to a positive reaction in more than 5% of the subjects. These concentrations were compared with the maximal concentration recommended for the diagnosis of sensitization to NMBAs. RESULTS: The maximal nonreactive concentrations were 10 m for suxamethonium; 10 m for pancuronium, vecuronium, rocuronium, and cisatracurium; and 10 m for atracurium and mivacurium. Except for mivacurium, these nonreactive concentrations were close to the maximal concentrations used for the diagnosis of sensitization against NMBAs. For mivacurium, the nonreactive concentrations were higher than the maximal concentration currently recommended in clinical practice. CONCLUSION: The aminosteroidal NMBAs pancuronium, vecuronium, and rocuronium and the benzylisoquinoline cisatracurium have a similar potency to induce a nonspecific skin reactivity. If the criteria for positivity and the maximal concentrations of the commercially available compounds recommended by French practice guidelines are used, the risk of false-positive results is limited, and only minor modifications of these recommendations could be suggested. A slight reduction in the maximal concentration used for rocuronium from 1:100 to 1:200 and an increase from 1:1,000 to 1:200 for mivacurium can be proposed.

The effect of neuromuscular block and noxious stimulation on hypnosis monitoring during sevoflurane anesthesia.

BACKGROUND: There are conflicting results on the influence of neuromuscular block (NMB) on the bispectral index (BIS). We investigated the influence of two degrees of NMB on BIS, Alaris auditory-evoked potential index (AAI), and the electromyogram (EMG) obtained with needle electrodes from the frontal and temporal muscles, immediately adjacent to the BIS-sensor. METHODS: Twenty patients were anesthetized with sevoflurane, titrated for 30 min to an end-tidal concentration of 1.2% (baseline). Rocuronium was infused to 50% (partial) and 95% (profound) depression of the first twitch in a train-of-four response, the order being randomly chosen. Noxious tetanic electrical stimulation was applied at four occasions: 1) at baseline (control measurement), 2 and 3) at each degree of NMB, and 4) after neostigmine reversal. BIS, AAI, and EMG were obtained 2 min before and 2 min after each noxious stimulation. RESULTS: Median BIS and AAI at baseline were 44 (39-50) and 15 (14-16), respectively. The two degrees of NMB did not affect BIS, AAI, and EMG before noxious stimulation. In contrast, profound NMB altered the BIS and AAI responses to noxious stimulation when compared with partial NMB, (BIS P = 0.01, AAI P < 0.01), after neostigmine reversal (BIS P < 0.01, AAI P = 0.01) and compared with baseline (BIS P = 0.08, AAI P = 0.02). No significant increase in EMG was found. CONCLUSION: BIS and AAI responses to noxious tetanic electrical stimulation are affected by the degree of NMB during sevoflurane anesthesia whereas NMB does not affect BIS or AAI in the absence of noxious stimulation.

Posttetanic count revisited: are measurements more reliable using the TOF-Watch accelerographic peripheral nerve stimulator?

OBJECTIVE: Measurement of profound neuromuscular block using posttetanic count is among the most subjective measurements made in clinical anesthesia. The TOF-Watch accelerographic peripheral nerve stimulator provides objective measurements of neuromuscular block that may improve our ability to quantitate intense blockade. METHODS: The TOF-Watch and Digi Stim III peripheral nerve stimulators were used to monitor onset and early recovery of neuromuscular response induced by rocuronium 0.6 mg/kg i.v. in 30 patients anesthetized with general anesthesia. After induction, train-of-four count (when present) was measured at one-min intervals. Subsequently, posttetanic count was measured at three-min intervals until the first response to train-of-four stimulation reappeared. RESULTS: Posttetanic count and train-of-four count measurements were determined to be consistently unreliable throughout the study in seven (23%) patients with the TOF-Watch stimulator and three (10%) patients with the Digi Stim III stimulator (p = NS). Among stimulators yielding reliable measurements, decreases in train-of-four count to 0/4 were noted earlier with the Digi Stim III monitor (median = 2 min) as compared with the TOF-Watch device (median = 4 min) (p < 0.05). Also, posttetanic count decreased to zero in only 35% of patients with the TOF-Watch stimulator versus 67% of patients with the Digi Stim III stimulator (p < 0.05). CONCLUSIONS: Both monitors were similar in their ability to predict return to TOFC = 1 as a function of PTC measurements. The TOF-Watch monitor is easy to apply even in inexperienced hands. However, the device yielded erroneous data in 23% of patients.

Risk of recurarization during retransfusion of autologous blood withdrawn after injection of muscle relaxants: a comparison of rocuronium and mivacurium.

STUDY OBJECTIVES: In the context of acute normovolemic hemodilution (ANH) recurarization, defined as significant decrease of train-of-four ratio (TOFR) during retransfusion of autologous blood withdrawn after induction of anesthesia, has been described for vecuronium and atracurium. The present study for the first time examined this risk for rocuronium and mivacurium. DESIGN: Prospective, randomized, unblinded clinical study. SETTING: University Hospital in Zurich/Switzerland. PATIENTS: 20 ASA physical status I and II patients undergoing general anesthesia for major maxillofacial surgery. INTERVENTIONS: Anesthesia was induced and maintained with propofol and remifentanil, and rocuronium (0.9 mg kg(-1)) or mivacurium (0.25 mg kg(-1)) was given to facilitate intubation. Thereafter, ANH was started with the removal of 500 mL autologous blood and the subsequent replacement by the same amount of 6% hydroxyethyl starch. The withdrawn blood was stored at 4 degrees C until retransfusion at the end of surgery. MEASUREMENTS: To estimate the risk of recurarization during retransfusion, the degree of recurarization during retransfusion of the autologous blood was assessed mechanomyographically. Plasma levels of rocuronium and mivacurium in the patients' plasma and the autologous blood were determined after its removal and before retransfusion. MAIN RESULTS: The TOFR before retransfusion was 0.97 (range: 0.96 to 0.98) for rocuronium (n = 10) and 0.98 (range: 0.96 to 1.0) for mivacurium (n = 8); n.s. During retransfusion, a slight, but statistically significant reduction of TOFR occurred in one patient in each group. In the mivacurium group, this recurarization occurred 10 minutes after the start of retransfusion; in the rocuronium group, it occurred 20 minutes after retransfusion. The plasma levels of rocuronium and mivacurium in the autologous blood did not change during storage. The plasma concentration of mivacurium in the autologous blood after its removal was 420 +/- 142 microg/L; before retransfusion, it was 384 +/- 147 microg/L. The respective concentrations for rocuronium were 2930 +/- 516 microg/L and 2660 +/- 464 microg/L. CONCLUSIONS: Recurarization during retransfusion may occur with both neuromuscular blocking drugs, mivacurium and rocuronium, when these drugs were injected before the removal of the autologous blood.